Conventionally, in an industrial furnace, a firing furnace, a heat-treatment apparatus or the like, as a lining material or a heat-insulating material for a ceiling, a wall or the like inside of a heating chamber, a relatively heavy refractory material such as brick has been used. In recent years, an inorganic fibrous shaped refractory article formed mainly of inorganic fibers has come to be used (see Patent Document 1 (JP-A-2001-192278), for example).
An inorganic fibrous shaped refractory article contains inorganic fibers, a binder for binding the inorganic fibers, and an inorganic filler which is optionally added. As the above-mentioned inorganic fibers, in order to improve the heat resistance as well as to reduce the density of the shaped article, ceramic fibers such as alumina silicate fibers have been used. As the above-mentioned inorganic filler, alumina powder or silica powder has been used in order to improve heat resistance.
However, since the inorganic fillers such as alumina powder or silica powder are expensive, there is a technical problem that the production cost and the product price of the inorganic fibrous shaped article are increased.
In the inorganic fibrous shaped article as mentioned above, some ceramic fibers or silica powder used have a high chemical resistance for a body fluid, and hence, possibility has been pointed out that they may adversely affect the health of a human body when they invade the lung by breathing.
Further, in an apparatus for casting aluminum, magnesium or the like, when a plurality of the above-mentioned inorganic fibrous shaped articles are combined to be used as a lining material of a member which contacts a molten metal, such as a drainpipe, a molten metal holding furnace and a ladel, a paste-like inorganic fibrous unshaped refractory composition is used in spaces between the combined articles (joint) or the like. Since this paste-like inorganic fibrous unshaped refractory composition is obtained by adding a liquid solvent to the same materials as those of the inorganic fibrous shaped refractory article, there is also a technical problem that the production cost and the product price are increased.